package com.example.e_comm.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.example.e_comm.entity.User;
import com.example.e_comm.mapper.UserMapper;
import com.example.e_comm.service.UserService;
import com.example.e_comm.util.RedisUtil;
import com.example.e_comm.util.TokenUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.DigestUtils;

import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.concurrent.TimeUnit;

/**
 * 用户服务实现类
 */
@Service
@Transactional
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {

    @Autowired
    private RedisUtil  redisUtil;
    @Autowired
    private TokenUtil tokenUtil;
    @Autowired
    private UserMapper userMapper;

    @Override
    public boolean register(User  user){
        //注册功能实现
        //查重
        if (this.count(new QueryWrapper<User>()
                .eq("username", user.getUsername())) > 0){
            throw new IllegalArgumentException("用户名已存在,请替换其他用户名！");
        }
        if (this.count(new QueryWrapper<User>()
                .eq("email", user.getEmail())) > 0){
            throw new IllegalArgumentException("邮箱已被注册！");
        }
        //密码加密
        if(user.getPassword() != null){
            throw new IllegalArgumentException("密码不能为空！");
        }
        user.setPassword(DigestUtils .md5DigestAsHex(user.getPassword().getBytes()));
        user.setStatus(1);
        return this.save(user);
    }


    //登录功能实现
    @Override
    public String login(String username, String password) {
        //登陆验证，验证书否正确输入username和password
        if(StringUtils.isEmpty( username) && StringUtils.isEmpty(password)){
            throw new IllegalArgumentException("用户名或密码不能为空！");
        }
        QueryWrapper<User> queryWrapper = new QueryWrapper<>(); //用于实现查询条件对象
        //根据用户名和密码查询用户状态在用的用户
        queryWrapper.eq("username", username)
                .eq("password", DigestUtils.md5DigestAsHex(password.getBytes()))
                .eq("status", 1);
        User user = this.getOne(queryWrapper);
        if (user == null) {
            throw new IllegalArgumentException("用户名或密码错误！请查证后重新操作");
        }
        //为找到用户生成Token
        String token = tokenUtil.generateToken();
        //将生成的token放到Redis缓存中，同时设定有效时长
        redisUtil.set("user:token:"+token, user.getId().toString(), 10, TimeUnit.MINUTES);
        //建立用户ID与token的映射
        redisUtil.set("user:id:"+user.getId(), token, 10, TimeUnit.MINUTES);
        return null;
    }

    @Override
    public User getUserByToken(String token) {
        //查找缓存Redis缓存中是否有token
        if (! tokenUtil.validateToken(token)) {
            return null;
        }
        //从Redis缓存中获取token用户ID
        Object userIdObj = redisUtil.get("user:token:"+token);
        if (userIdObj == null) {
            return null;
        }
        try{
            Long userId = Long.valueOf(userIdObj.toString());//获取Redis中的UserId
            //根据用户ID查DB
            User user=this.getById(userId);
            if (user != null) {
                //刷新Token的值
                redisUtil.set("user:token:"+token, user.getId().toString(), 10, TimeUnit.MINUTES);
                redisUtil.set("user:id:"+user.getId(), token, 10, TimeUnit.MINUTES);
            }
            return user;
        }catch(Exception e){
            System.err.println("没有找到与这个Token适配的、User" + e.getMessage());
            return null;
        }
    }

    @Override
    public boolean logout(String token) {
        User user=getUserByToken(token);
        if (user != null) {
            //刷新Token的值
            redisUtil.delete("user:token:"+token);
            redisUtil.delete("user:id:"+user.getId());
            return true;
        }
        return false;
    }

    //验证Token
    @Override
    public boolean validateToken(String token) {
        return redisUtil.hasKey("user:token:"+token);
    }













    @Override
    public List<User> getUsersByRoleId(Long roleId) {
        if (roleId == null || roleId <= 0) {
            return Collections.emptyList();
        }
        return userMapper.getUsersByRoleId(roleId);
    }

    @Override
    public User getUserByUsername(String username) {
        if (username == null || username.isEmpty()) {
            return null;
        }
        return userMapper.selectByUsername(username);
    }

    @Override
    public List<User> getUsersById(Long userId) {
        if (userId == null || userId <= 0) {
            return Collections.emptyList();
        }
        return userMapper.getUsersById(userId);
    }

    @Override
    public List<User> getUsersByIdSet(Set<Long> userIdSet) {
        if (userIdSet == null || userIdSet.isEmpty()) {
            return Collections.emptyList();
        }
        return userMapper.getUsersByIdSet(userIdSet);
    }
}

